1. Field of the Invention
The present invention relates to a device and a method for controlling sound, more particularly the present invention relates to a device and a method for controlling the phase of sound data to give width of sound
2. Description of the Related Art
Conventionally, various effect devices for controlling the frequency components of a musical tone have been known. One of these effect devices is a digital filter. A signal input to this digital filter has not only the gain of each frequency component shifted, but also the phase of each component shifted.
The phase shift of an output signal relative to the phase of the signal which is input to such a digital filter is not constant over all frequencies. Also, the phase shift value differs according to the frequency value. A signal passing through this filter has the gain of a specific frequency component shifted, but also has the phase shifted. Rather, an excessive shift is given to a musical tone. This was not preferred in terms of the quality of the sound.
Contrary to this, it is also possible to consider the use of an all pass filter allowing signals of the entire frequency band to pass through. However, even with an all pass filter, the shift of the phase of the signal which is output relative to the phase of the signal which is input is still not constant in all frequencies. It is desirable that the phase difference between an input signal and an output signal be constant in the entire frequency band from the viewpoint of the width of sound.